Sir Menzies said it was essential that the party better reflected the make-up of modern British society.

The Liberal Democrats have already launched a £200,000 diversity fund to support candidates from under-represented groups - including women as well as ethnic minorities.

"Since being elected as Liberal Democrat leader, I have made a personal commitment to making my party more representative of the communities we serve," Sir Menzies said.

"I want to encourage people who have not previously engaged in politics to join us, get selected and get elected."

The initiative was welcomed by the head of Operation Black Vote, Simon Woolley.

"We are working with the Liberal Democrats to help build an effective platform to gain more black and minority members, more directly elected BME politicians and greater confidence for BME communities to vote for them," he said.